Combustion-chamber construction for internal combustion engines



Aug.. 23, 1960 H. M. JAcKLlN 2,949,899

COMBUSTION-CHAMBER CONSTRUCTION FOR INTERNAL COMBUSTION ENGINES Original Filed Oct. 6, 1950 INVENTOR /L//wa 'ICKL/N,

COMBUSTION-CHAlER 'CONSTRUCTION FOR INTERNAL CGMBUSTION ENGINES Harold M. Jacklin, 1916 N. Meridian St., Indianapolis, Ind.

Original application Oct. '6, 1950, Ser. No. 188,810,

now Patent No. 2,805,654, dated Sept. 10, 1957. Divided and this application Sept. 9, 1957, Ser. No.

13 Claims. (Cl. '12S-32) gine continues to operate, and to provide such temperature control in a simple, effective, and economical manner.

In carrying out the invention, I provide the combustion space or chamber with a liner which, when the engine is cold, has limited or poor contact with its enclosing walls which are cooled in one way or another. When the engine is started, the liner warms up quickly, as its poor contact with the surrounding Walls retards the escape of the heat received by the liner from the combustion process. As the temperature of the liner rises, it expands into more effective heat-transmitting contact with the `surrounding'wall, and the resultant increase in heat transmission to the wall prevents the liner from becoming overheated.

-ln the accompanying drawings:

Fig. 1 is a section through an engine on the axis of one cylinder;

Fig. 2 is a section on ythe line 2 2 of JFig. l; and

Fig. 3 is a ragmental view similar to Fig. l but on an enlarged scale illustrating details of the combustion chamber.

The engine shown by way of example in Fig. l is of the opposed piston type and, in its entirety, is more ful-ly set forth and described in my prior United States Patent No. 2,805,654, issued September l()I 1957. Such engine comprises a lower block 30 having one or more inlet cylinders 31, an upper block 32 having a corresponding number of exhaust cylinders 33, and a head 34 which is interposed between the two blocks and which is provided with a combustion chamber 35 in line with each pair of inlet and exhaust cylinders. Any appropriate form of means, such as the through-bolts 36, may be used to hold the two blocks and the head in assembled relationship. Each inlet cylinder 31 contains an inlet piston 37 connected by a yconnecting rod 38 to a crank 39 of a lower crank shaft 40; In a position to be uncovered by the head of the piston 37 as it nears the outer end of its stroke, the cylinder 31 is provided with inlet ports 42 which communicate with an air box 43 and which may be directed tangentially so lth-at the gases entering the cylinder through 4them will create a circular motion within the cylinder.

Each exhaust cylinder 33 is aligned with and conveniently of the same diameter as an inlet cylinder 31 and contains a reciprocable piston 50 connected through a connecting rod 51 with a crank pin 52 of an upper crank shaft 53, which is operatively connected to the lower crank shaft 40 as through gearing 56. The stroke of 2,949,899 Patented Aug. 23, 1960 the upper piston 50 is considerably less than that of the lower piston, preferably being about one-third to onehalf of the stroke of the lower piston. In a position to be uncovered by the piston 50 as it nears the outer end of its stroke, the cylinder 33 is provided with an annular series of exhaust ports 54 the axes of which desirably are inclined outwardly of the cylinder in both radial and axial senses.

The combustion chamber 35 in ythe head 34 is of smaller diameter than the cylinders 31 and 33 to provide annular shoulders which are closely approached by the pistons 37 and 50 at the inner ends of their strokes. For a purpose which will become apparent hereinafter, the combustion chamber 35 is provided with a sleevelike liner 61 which, when cold, is of slightly smaller diameter than the opening in the head which receives it. Such liner may be held in place against both axial and rotational movement by radially extending pins 62 which are removably mounted in the head 34 and project into openings in the liner 61.

In the particular engine illustrated in the drawing, which is of the fuelinjection type, the head 34 is provided at each combustion chamber with a fuel-injector adapted to discharge into the associated combustion chamber 35through an Vappropriately positioned opening 71 in the liner 61. Desirably, the injector 7i) is yso oriented that it discharges chordally into the combustion chamber toward an ignition device 72 which is mounted in the block 31D and exposed through an opening 73 in the liner 61.

Fig. l illustrates the positions of the pistons 37 and 50 near the inner ends of their strokes a short interval after the occurrence of the explosion. As the pistons are driven outwardly under the iniluence of the expanding gases, the two crank shafts 4t) and 53 rotate in the clockwise direction, as indicated by the arrows in Fig. 1, expansion of `the gases continuing until the exhaust piston 50 uncovers the exhaust ports `S4. Shortly after the exhaustjports Iare uncovered, `the inlet piston 37 uncovers the inlet ports 42 to admit the new charge. Such charge tlows generally upwardly in the cylinders and, forcing -the products of combustion -ahead of it, produces the necessary scavenging action. As rotation of the crank shafts continues, the exhaust ports close in the inward movement of the exhaust piston Sti and, shortly thereafter, the inlet ports 42 are closed by inward movement of the inlet piston 37. Compression and the next explosion follow.

The upper and lower clinders and the head 34 are provided with innercommunicating water jackets through which the water or other coolant successively circulates. As shown in the drawing, the water jacket for the lower cylinder is in two sections and 81 lying respectively below and above the inlet ports 42, -the two sections being interconnected as by a conduit 83 bridging the ports. The upper cylinder has an `axially continuous coolant-receiving space 84 across which exhaust passages 54 extend to connect with exhaust conduits 85. The head 34 (Figs. l and 3) has a annular coolant chamber 86 communicating with ports 87 which open into the upper and lower faces of the head in position to communicate with annular grooves 88 and 89 provided respectively in the lower face of the upper cylinder block 32 and in the upper face of the lower cylinder block 30. Ports 90 in the upper cylinder block provide communication between the coolant receiving space 84 and groove 88, while ports 91 provide communication between the upper jacket section 81 of the lower cylinder and the annular groove 89. The ports 87 are angularly displaced from the ports 90 and 91 so that the coolant leaving each port 91 in the lower cylinder block will be compelled to flow circumferentially for a distance along the groove 89 before entering `a lower port 87 of the head. Similarly, coolant leaving each upper port 87 of the head must flow circumferentially for a distance along ythe groove S8 before entering a port 90 and passing up wardly `through the jacket of the upper cylinder. The ports 90 and 91, which are desirably drilled, are equally spaced about the cylinder-axis; and the circumferential ow of liquid in contact with the end faces of the cylinder barrels aids very materially in cooling the inner ends of the cylinder barrels to promote improved lubrication and reduce wear thereat and maintains .the head at a lower ytemperature than would otherwise be possible.

Reference has heretofore been made to ythe combustion-chamber liner 61 and to its normal loose ft Within the head 34. When the engine is first started, the loose fit of the liner 61 within the head 34 retards the transfer of the heat from the liner to the head, with the result that the liner warms up quickly. As l-inentemperature increases, the l-iner expands, the fit between it and the head 34 becomes tighter, and heat transfer from the liner to the head becomes more rapid. Thus, under star-ting conditions when the engine is cool, the temperature of the liner increases quickly and promotes satisfactory combustion. At ythe same time, the liner is prevented from becoming overheated as the engine continues in operation, because any tendency to overheat increases the tightness of its t within the head 34 and thereby increases the rate of heat transfer to the cooled head.

It will be understood that the particular engine shown and `described is set forth merely by way of example and that the invention to which lthis application relates is a loose combustion chamber liner one form of which is shown at 61. The use of such `a liner is not limited to opposed-piston engines or to a combustion chamber located in a cylinder or between cylinders. It is only necessary that the liner have, at low temperatures, a relatively loose fit within its enclosing wall to provide poor heat transmission to such Wall and that it expand into more effective heat-transmitting contact with the wall when its temperature rises.

'This application is a division of my prior application 4 Serial No. 188,810, tiled October 6, 1950, which resulted in my aforesaid patent No. 2,805,654.

I claim as my invention: -t

1. In an internal combustion engine having a cylinder and a combustion chamber, said combustion chamber having a cooled annular wall, an annular liner for said combustion chamber, said liner having a loose t in said combustion chamber providing poor heat transmission to the wall thereof at ylow temperatures but being capable of expanding into iirm contact with the chamberwall under the influence of heat received from burning gases in operation of the engine, said combustion chamber communicating with said cylinder lthrough an opening having a diameter equal at least to t-he external Ydiameter of said liner whereby any annular gap between the liner and -tbe surrounding wall of the combustion chamber will be in free communication with the cylinder.

2. In an opposed-piston engine having a combustion chamber disposed between two coaxial cylinders, said combustion chamber being of substantially uniform diameter between its openings into said cylinders, an annular liner for said combustion chamber, said liner fitting loosely in said chamber when it and the surrounding chamber wall are at ythe same temperature but being capable of expanding into rm heat-transmitting contact with such chamber-wall under the influence of heat received from burning 4gases within the liner, and means located between the ends of said liner for maintaining it in yfixed axial position.

3. An engine as set forth in claim 2 with the addition that said means comprises generally radial pins secured in Ithe wa-ll of the combustion chamber and received in openings in said liner.

References Cited in the nle of this patent UNITED STATES PATENTS 1,410,319 Junkers Mar. 2l, 1922 1,486,583 Huskisson Mar. 11, 1924 1,595,148 Gardner Aug. 10, 1926 2,705,478 Jacklin Apr. 5, 1955 2,868,181 Dolza Ian. 13, 1959 

